Vitamin D-3, having gained scientific interest for so long because of its r
ole in mineral homeostasis, has now received great importance as a possible
antitumor agent. This study was undertaken in an attempt to visualize the
possible anticlastogenic potential of the vitamin in an ascitic mouse lymph
oma model namely, Dalton's lymphoma. Frequencies of structural type chromos
omal aberrations, sister chromatid exchanges and micronucleus assays have b
een chosen as the genotoxic endpoints in the proposed investigation. All th
ese cytogenetic markers have been found to be markedly elevated during the
progression of lymphoma in bone marrow cells. Vitamin D-3 effectively suppr
essed the frequencies of chromosomal aberrations and sister chromatid excha
nges in the lymphoma-bearing mice during the entire phase of tumor growth t
hat significantly coupled with almost two-fold increase in survival time (3
7 +/- 2 and 68 +/- 2 days in lymphoma controls and vitamin D-3-treated lymp
homa bearing mice, respectively), thus substantiating the antineoplastic ef
ficacy of this secosteroid. The outcome of this study also is clearly refle
cted in the depletion of circulating (serum) vitamin D-3 levels in the lymp
homa control mice compared with normal (vehicle) controls while a still hig
her level was maintained in the VD3-treated lymphoma mice. This anticlastog
enic property of the vitamin has so far been neglected and this is the firs
t attempt to unravel the vitamin D-3's effect in combating tumor developmen
t in vivo by limiting the frequencies of chromosomal aberrations, sister ch
romatid exchanges and micronuclei at least in transplantable murine model s
tudied herein. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.